Resolution: In my case I was using PXE Everywhere v2.2 which will support laptops with UEFI as well as Legacy boot options. However, tablets like the Venue 11 Pro are native UEFI and this is currently not supported! I big surprise considering the demands on Enterprise IT to deploy Windows 8.1 as just another OS (JAOS we'll see if it catches on). 1e reported that in v2.3 due later this year (todays date: 22/09/2014) UEFI native will be fully supported.